Problem fixed! I bought a set of standard flare nut wrenches. For the record, the size on the line at the gear box is 5/8" and the one at the firewall going into the wiper motor is 11/16".
I cleaned the gear box opening with brake parts cleaner and a pipe brush. Tightened the fitting at the gear box and then the one at the firewall. The flare nut wrenches definitely added some ability to safely apply torque.
Thanks for the responses. I took a video of the car at idle that I posted a link to in the Off Topic section
here.